Metal coating



F. KELLEY METAL comma June 22 1926.

Filed May 10, 1920 W /J A u? y E r% n E w t mc mmfi W 3 1% m P Patented June 22, 1926.

UNITED, STATES, PATENT, OFFICE,

FLOYD C. KELLEY, F SCHENECTADY, NEW YORK, ASSIGNOR TOGENERAL ELECTRIC COMPANY, CORPORATION OF NEW YORK. r

METAL COATING.

"Application filed May 10, 1920. Serial No. 380,023.

The present invention relates to the coating of cast iron with other metal and particularly to the production of a composite article of cast iron and a nonferrous metal.

Gre at difficulty has been experienced in causing cast iron to unite with a non-ferrous metal, for example, copper, in such a -way as to'produce a thoroughly adherent coating or union. Heating the metals to be united in hydrogen does not cause the copper to wet the cast iron as isthe case when copper in a molten state is brought into contact with steel in the presence of hydro gen. Fluxes likewise fail to' produce an adherent coating between cast iron and copper,

. or the like, when used in the usual way in contact with air.

T have discovered that a homogeneously adherent union between cast iron and a non-ferrous metal of lower melting point,

such as copper, silver or brass can be produced by applying the molten non-ferrous metal to the cast iron to I a/coated in a reducing atmosphere in the presence of a flux, particularly cryolite.

In accordance with my :invention, cast iron articles. intimately united with brass or other suitable cupreous metal, may be pro-v duced; The cupreousjmetal in turn may be united with a layer of other metal, such for example, as Babbitt metal which otherwise could not be integrally united with cast lIOIl.

The accompanying drawing illustrates in section a bearing made by'the practice of a process embodying my invention.

In accordance with one method of carrying out my invention a body of castiron 1 to be oined to a metal layer 2 of copper, silver or the like is heated in any convenient way, as for example, in an ordinary gas flame, to about 750 to 800 0., whereby the surface of the cast iron is oxidized. A

suitable flux, preferably cryolite, then is dis-.

tributed uniformly over the heated surface as by applying the cryolite in powdered form upon the oxidized surface of the cast I iron. The cryolite is brought to fusion on the heated cast iron, and the iron surface coated with cryolite flux is brought into contact with molten copper, brass or the like in a hydrogen atmosphere. For example, a

piece of copperwire may "be wrapped about the cast iron and the iron with the copper heated tov the melting point of copper in a' hydrogen furnace. If thecryolite has been properly distributed before melting the copper, a uniform coating 2, of copper results which when molten wets the cast iron in such a way as to resist mechanical se ara-' tion when solidified. The heating 0 the cast iron to a temperature of about 7 50 to 800 C. in an ordinary gas flame decarburizes the surface of the cast iron or, in other words, oxidizes the carbon out of the surfaces of the cast iron, and whatever oxide of the iron is formed is subsequently reduced by the hydrogen.

Ailayerof Babbitt metal 3 may be cast against the layer of copper. A hearing thus produced maybe supported on a suitable frame at. Only one-half of the hearing enclosing the shaft 5 has been illustrated.

When cast iron is to be coated with silver, I prefer to employ borax as a flux- In the appended claims, I have set forth the novel features of my invention with particular reference to copper but I wish it to be understood that my invention is equally applicable to coating cast iron with other metals, as for example, brass. I

What I claim as new and desireto secure by Letters Patent of the United States,

face in a hydrogen atmosphere.

3. The-method of coating cast iron with a non-ferrous metal of lowermelting point than cast iron which consists in heating the cast iron to about 750 to 800 7. in an oxidizing flame and thereupon applying 1. The method of coating cast iron with said non-ferrous metal to the oxidized surface of the cast iron, applying a flux upon face in the presence of both a flux and a resaid surface, fusing said flux and applying ducing gas. copper in a fused state and in a hydrogen 10 4E. The method of producing an adheratmosphere to the flux coated surface. 5 ent coating of copper upon cast iron which In Witness whereof, I have hereunto set comprises first heating the cast iron in an my hand this 7th day of May, 1920. open flame to thereby decarburize the sur- FLOYD C. KELLEY. 

